Image Size When Using Flare as an External Editor

When I use Flare as an external editor from iPhoto,
Aperture, or Lightroom it ends up increasing the file size of my
image. Why?

Flare's default image compression errs on the side of higher
quality, which makes for a larger file size than the compression
settings on many cameras. Additionally, adding filters and textures
to an image can make it more visually complex, which can also
result in a larger file size.

To reduce the file size of the JPG that Flare saves back to
iPhoto, you need to set the JPG compression to a lower value. This
can't be done directly, but you can use this workaround: Open an
image directly in Flare (not via iPhoto), then save it as JPG. Set
the quality to the desired amount - the lower the quality, the
smaller the file size will be. Flare will now remember that quality
setting when used as an external editor for iPhoto. Keep in mind
that lowering the quality like this is actually degrading your
image - you'll need to find the right balance between image quality
and file size.